screws for roof mounting

[ChRoNo16]

how long of screws are safe to use for mounting something to the roof inside the cab?

I wants to mount my cb radio and all i have are 3/4" self tappers

 

[Drunkcanuk]

how long of screws are safe to use for mounting something to the roof inside the cab?

I wants to mount my cb radio and all i have are 3/4" self tappers

You should be ok. Depending on the thickness of what you are attaching.
When I had my headliner out a few years ago it seems like there was about 3/4" between the two layers.
But please don't take my fuzzy memory as 100% fact!!!
You can drill a small pilot hole first to double check the depth by drilling the first layer then measure how far it takes to touch the top one.

 

[GrimsterGMC]

You will be lucky if there is a half inch between layers, when I installed my roof console I did what @Drunkcanuk said and drilled a test hole and poked a piece of wire into it as a depth gauge.

 

[454cid]

I think I'd be afraid of it falling, either due to vibration or a collision (deer, car, whatever). I'd rather have it down low. Unless maybe newer CBs are lighter than the old ones I've seen.

 

[GrimsterGMC]

I think I'd be afraid of it falling, either due to vibration or a collision (deer, car, whatever). I'd rather have it down low. Unless maybe newer CBs are lighter than the old ones I've seen.

I agree, also have to be sure there are no sharp edges in case of a rollover, as that area is always pushed down to meet your head.